drm/panel: sitronix-st7789v: avoid hardcoding invert mode

While the default panel uses invert mode, some panels
require non-invert mode instead.
Reviewed-by: Michael Riesch <michael.riesch@wolfvision.net>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230714013756.1546769-12-sre@kernel.org

drivers/gpu/drm/panel/panel-sitronix-st7789v.c

@@ -112,6 +112,7 @@
 struct st7789_panel_info {
 	const struct drm_display_mode *mode;
 	u32 bus_format;
+	bool invert_mode;
 };
 
 struct st7789v {
@@ -171,6 +172,7 @@ static const struct drm_display_mode default_mode = {
 
 static const struct st7789_panel_info default_panel = {
 	.mode = &default_mode,
+	.invert_mode = true,
 	.bus_format = MEDIA_BUS_FMT_RGB666_1X18,
 };
 
@@ -321,7 +323,13 @@ static int st7789v_prepare(struct drm_panel *panel)
 	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_VN61(0x1b)));
 	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_VN62(0x28)));
 
-	ST7789V_TEST(ret, st7789v_write_command(ctx, MIPI_DCS_ENTER_INVERT_MODE));
+	if (ctx->info->invert_mode) {
+		ST7789V_TEST(ret, st7789v_write_command(ctx,
+						MIPI_DCS_ENTER_INVERT_MODE));
+	} else {
+		ST7789V_TEST(ret, st7789v_write_command(ctx,
+						MIPI_DCS_EXIT_INVERT_MODE));
+	}
 
 	ST7789V_TEST(ret, st7789v_write_command(ctx, ST7789V_RAMCTRL_CMD));
 	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_RAMCTRL_DM_RGB |